Ran a grep to find unneccessary NULL checks before free(3) and found some in dhclient(8) and makefs(8).
Geoff Hill Index: sbin/dhclient/dhclient.c =================================================================== RCS file: /cvs/src/sbin/dhclient/dhclient.c,v retrieving revision 1.659 diff -u -p -r1.659 dhclient.c --- sbin/dhclient/dhclient.c 26 Jan 2020 10:31:03 -0000 1.659 +++ sbin/dhclient/dhclient.c 7 Apr 2020 23:38:50 -0000 @@ -2315,8 +2315,7 @@ fork_privchld(struct interface_info *ifi go_daemon(); - if (log_procname != NULL) - free(log_procname); + free(log_procname); rslt = asprintf(&log_procname, "%s [priv]", ifi->name); if (rslt == -1) fatal("log_procname"); Index: usr.sbin/makefs/ffs.c =================================================================== RCS file: /cvs/src/usr.sbin/makefs/ffs.c,v retrieving revision 1.31 diff -u -p -r1.31 ffs.c --- usr.sbin/makefs/ffs.c 21 Jan 2017 21:58:32 -0000 1.31 +++ usr.sbin/makefs/ffs.c 7 Apr 2020 23:38:52 -0000 @@ -448,8 +448,7 @@ ffs_create_image(const char *image, fsin } bufrem -= i; } - if (buf) - free(buf); + free(buf); /* make the file system */ if (Tflag) { @@ -706,8 +705,7 @@ ffs_populate_dir(const char *dir, fsnode } /* cleanup */ - if (dirbuf.buf != NULL) - free(dirbuf.buf); + free(dirbuf.buf); return (1); } @@ -803,8 +801,7 @@ ffs_write_file(union dinode *din, uint32 ffs_write_inode(&in.i_din, in.i_number, fsopts); leave_ffs_write_file: - if (fbuf) - free(fbuf); + free(fbuf); if (ffd != -1) close(ffd); }